It is well-known that the main advantages of using light emitting diode (LED) lamps are long lifetime and low energy consumption when compared to conventional lighting technologies, such as incandescent lamps and florescent lamps. Therefore, many governments are encouraging residential users and electricity providers to replace conventional lighting sources with LED lamps to endorse energy savings. Since most of LED lamps are for residential applications, rated power per lamp is usually from 5 to 30 W, Power Factor Correction (PFC) requirement is not applied to those products, such as EN61000-3-2. Thus, some low cost LED lamps generate harmonic currents to the grid that affects the power system network when lamps are used in a large scale lighting system such as a street lighting network and a parking building lighting network. Researchers have analyzed the harmonics emission of large penetration of LED lamps, in which it was found that the nonlinear characteristics of the LEDs result in a low Power Factor (PF), around 0.5, with total harmonic distortion (THD) between 80-150%. In addition, LED lamps are sensitive to power system disturbances like a voltage sag. Even though a voltage sag lasts for few milliseconds, it may cause the lamp to flicker or even get damaged in some cases. Especially lighting networks which are located near large industrial facilities, such as for example an electric arc furnace, voltage flickers make light intensity changing accordingly. Several studies were conducted on improving the LED performance focusing on enhancing the design of the internal ballast circuit, however those techniques add more complexity and cost to the system, while focusing on power factor correction only. Another simple method is to connect capacitors in front of the ballast. The drawback of this method is, if the load impedance has changed, the degree of power factor correction cannot respond since the capacitors are passive components.
Accordingly, systems and methods that enable improved power quality provided to largescale LED lighting networks remains highly desirable.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.